Process for the preparation of 1-amino-2-alkyl-mercapto-4 hydroxy-anthraquinones



Patented May 26, 1953 PROCESS FOR THE PREPARATION OF1-AMINO-2-ALKYL-MERCAPTO-4 HY- DROXY-ANTHRAQUINONES George W. Seymour,Maplewood, and Victor S, Salvin, Irvington, N. J., assignors to CelaneseCorporation of America, New York, N.'Y., a corporation of Delaware NoDrawing. Original application May 7, 1947,

Serial No. 746,634. Divided and this application July 29, 1952, SerialNo. 301,606

1 Claim. (01. zed-380) This invention relates to novel anthraquinonedyestufis and relates more particularly to certainmercapto-anthraquinone dyestuifs of excellent fastness properties.

An important object of this invention is the production of improvedanthraquinone dyestuffs dyeing cellulose acetate or other organicderivative of cellulose textile materials in desirable red shades fastto light, washing and acid-fading.

Other objects of this invention will appear from the following detaileddescription.

This application is a division of U. S. application Serial No. 746,634,filed May '7, 19%.

Various azo and anthraquinone dyestuffs dyeing cellulose acetate orother organic derivative of cellulose textile materials in desirable redshades are available. The red dyestuffs which are of azo structure arefairly satisfactory with respect to their resistance to acid-fading buttheir light fastness leaves much to be desired. On the other hand, theavailable red dyestuffs of anthraquinone structure while exhibitingexcellent light fastness are rather poor with respect to theirresistance to acid-fading. The preparation of dyestuffs which aresuitable for dyeing cellulose acetate or other organic derivative ofcellulose textile materials in red shades resistant both to acid-fadingand to light as well as to other agencies normally having a. deleteriouseffect on said dyed materials constitutes a distinct advance in the art.

We have now found that anthraquinone dyestuffs of the following generalformula wherein n is a Whole number and X is either a. hydrogen orhydroxy radical, exhibit an unusual degree of afiinity for celluloseacetate or other organic derivative of cellulose textile materials anddye such materials in valuable red shades which are of excellentresistance to light, washing and acid-fading. In addition, saiddyestufis may also be employed as pigments and excellent results may beobtained when incorporated in the cellulose acetate dope or spinningsolution and the latter then spun .or shaped into filaments or othermaterials.

Our novel dyestuffs may be obtained by reacting 1-amino-2,l-dibrom-anthraquinone with a mixture of boric acid and sulfuric acid toform 2 1-amino-'2 brom-4-hydroxy-anthraquinone, and reacting the latterwith sodium disulfide so that 1amino-'2-mercapto-4-hydroxy-anthraquinone is obtained. ThisI-aminO-Z-mercaptoi-hydroxy-anthraquinone intermediate may then bereacted under reflux in an alkaline medium with a chlorhydrin as, forexample, ethylene ohlorhydrin, 1,3-propylene 'chlorhydrin, 1,4- butylenechlorhydrin, 1,8-octamethylene chlorhydrin or -l,l2-dodecamethylenechlorohydrin or with a suitable alkyl halide such as methyl iodide,butyl bromide or lauryl chloride, or with dimethyl sulfate, to form thedesired substituted mercapto dyestuffs. We may thus obtain anthraquinonedyestufis such as, for example, 1- amino 2methyl-mercaptol-hydroxy-anthraquinone, 1amino-2-hydroxyethyl-mercapto4=- hydroxy-anthraquinone,l-amino-Z-hydroxypropyl-mercapto-4-hydroxy-anthraquinone, 1 -amino 2hydrexybutyl-mercapto 4-hydroxy-anthraquinone,1-amino-2-'hydroxyoctyl-mercapto- 4 hydroxy-anthraquinone,l-amino-Z-hydoxylauryl-mercapto 4 hydroxy-anthraquinone or 1amino-Z-lauryl-mercapto-4-hydroxy-anthraquinone. Suitable alkalineagents which may be employed for rendering the reaction medium alkalineare, for example, sodium hydroxide, sodium bicarbonate. magnesiumhydroxide, or sodiumcarbonate.

In order further to illustrate our invention, but without being limitedthereto, the following examples are given:

Example] 30 parts by weight of l-amino-ZA-dibrom-anthraquinone aredissolved in 200 parts by weight of concentrated sulfuric acid and 20parts by weight of boric acid are added thereto. The solution obtainedis heated with stirring for 8 hours at 150 C. During the reaction,hydrogen bromide and some free bromine are evolved. The reaction mixtureobtained is cooled, dropped on to ice and1-amino-2-brom-4-hydroxy-anthraquinone precipitates out as a red solid.The latter is filtered ofi and then washed free of acid.

A mixture of about 160 parts by weight of ethyl alcohol, 10 parts byweight of sulfur and 28 parts by weight of crystalline sodium sulfideare heated together until complete solution is obtained and then 20parts by weight of l-amino- 2-brom-4-hydroxy anthraquinone are added.The reaction mixture is maintained under reflux for 6 hours during whichtime the color changes from a wine to a Violet. After heating iscompleted the reaction mixture is acidified with dilute hydrochloricacid and the l-amino-Z-mercapto- 4-hydroxy-anthraquinone presentprecipitates together with sulfur. The precipitate is filtered fromsolution and the crude press cake obtained resludged in 500 parts byweight of 1% aqueous sodium hydroxide solution. The anthraquinonecompound passes into solution and the insoluble residual sulfur may beremoved by a second filtration. The alkaline filtrate of1-amino-2-mercapto-4-hydroxy-anthraquinone is then refluxed with about30 parts by Weight of ethylene chlorhydrin. Reaction takes place rapidlyand after one hour a red suspension ofl-amino-Z-hydroxyethyl-mercapto-4-hydroxy-anthraquinone is obtained.After filtration, the dyestuff is obtained in the form of a brown presscake. A yield of about 73% of theoretical based on the 1-amino-2-brom-4-hydroxy-anthraquinone is obtained. The dyestufi 1amino-2-hydroxyethyl mercapto-4- hydroxy-anthraquinone dyes celluloseacetate materials in attractive red shades and exhibits an excellentdegree of afiinity for said materials. Thev dyed cellulose acetatematerials may be exposed to ultra-violet light for 50 hours withoutfading and exhibit a resistanceto acid fading of 1.8 units in accordancewith the standard A. A. T. C. C. acid-fading test.

Example II To 300 parts by weight of an alkaline solution of 1amino-2-mercapto-4-hydroxy anthraquinone containing 8 parts by weight ofthe latter are added 13.25 parts by weight of dimethyl sulfate and 5parts by weight of caustic soda. The reaction mixture is held at 80 C.for 3 hours. The 1-amino-2-methylmercapto-4-hydroxy anthraquinone whichprecipitates is filtered oil and Washed. A yield of 62% of thetheoretical is obtained. The dyestuifl-amino-Z-methylmercapto-4-hydroxy-anthraquinone dyes cellulose acetatematerials in red shades with good affinity. The dyed cellulose acetatematerials may be exposed to ultra-violet light for 50 hours withoutnoticeable fading and exhibit a resistance to acid-fading of 1.8 unitsin accordance with the standard A. A. T. C. C. acid-fading test.

Example III To 200 parts by weight of an alkaline solution of1-amino-2-mercapto-4-hydroxy anthraquinone prepared and isolated as inExample I and containing 8 parts by weight of intermediate are added 80parts by weight of ethyl alcohol and parts by weight of lauryl chloride.The mixture is held under reflux at 85 C. for 2 hours, whence theformation of 1-amino-2-1auryl-mercapto-4-hydroxy-anthraquinone iscomplete. The dyestuff is isolated by filtration and may berecrystallized from alcohol. The1-amino-2-laurylmercapto-4-hydroxy-anthraquinone dyes cellulose acetatein red shades. The dyed acetate material does not noticeably changeafter exposure to ultra-violet light for 50 hours and it exhibits aresistance to acid-fading of 2.0 units in accordance with the standardA. A. T. C. C. acid-fading test.

While our invention has been more particularly described in connectionwith the dyeing of cellulose acetate materials, textile materials havinga basis of other organic derivatives of cellulose may be dyed with ournovel dyestuffs as well. Examples of other organic derivatives ofcellulose are cellulose esters such as cellulose propionate, cellulosebutyrate, cellulose acetatepropionate, cellulose acetate-butyrate aswell as cellulose ethers such as ethyl cellulose and benzyl cellulose.

It is to be understood that the foregoing detailed description is givenmerely by way of illustration and that many variations may be madetherein without departing from the spirit of our invention.

Having described our invention, what we desire to secure by LettersPatent is:

Process for the production of 1-amino-2-methyl-mercapto 4hydroxy-anthraquinone which comprises reacting1-amino-2-mercapto-4-hydroxy-anthraquinone under reflux in an aqueousalkaline medium with dimethyl sulfate.

GEORGE W. SEYMOUR. VICTOR S. SALVIN.

References Cited in the file of this patent UNITED STATES PATENTS OTHERREFERENCES Lowy et al.-Introduction to Organic Chemistry, 6th edition,pages 213-14 (1946) John Wiley 0 '& Sons, New York city.

